Which institution kept learning alive in europe during the middle ages?

The Middle Ages were the time where population decline, invasions, and movement of peoples away from the cities hampered economic development and learning. The only institution that preserved Roman texts about technology, politics and other sciences is the Church.  The structure of the Church, and the million hours of labor done by monks in writing and translating books, helped the population during times of  endured economic and civic upheavals.

the mongolian invasion of china and central asia resulted in a disruption of the silk road as the chinese garrisons lost support from the chinese kingdoms which fell under the mongols. however, as the mongols established a formal dynasty in china, the successors of genghis khan restored the garrisons along the silk road allowing the safe travel caravans again.